Manifold Off...... argggggg

[Darrendude]

Ok guys , I removed my manifold just now. I let the bolts soak overnite after spraying PB on it. Just as I was affraid of , Broke one bolt (#1 cyl) and Both bolts on # 4 stripped the head . I made nifty work with a dremel tool and cut them off. After further inspection with manifold off, I noticed 2 other hairline cracks.<br /><br />So now I need a new manifold and I want a new riser also. Where do I get them and what do I need? I cant read the numbers off the manifold,looks to be 4 numbers maybe 66 are the first #'s, the numbers on the riser are mc 20 5553 (3 or 8) cant read the last number. My engine serial number is 4525255.<br /><br />Any help<br /><br />Thanks all

 

[Darrendude]

Re: Manifold Off...... argggggg

will this work on my motor, I know it sez 181 c.i. mine is a 153. But it also sez 120hp. It is from Manifold Warehouse and they have free shipping.<br /><br />MC-1-52390<br />Mercruiser 4-cylinder manifold<br />181 cu.in. 140h.p. Model 120/140 engine 2.5L/3.0L<br /><br /> http://www.manifoldwarehouse.com/mani_mercruiser.htm

 

[Laddies]

Re: Manifold Off...... argggggg

I don't have there catalog, but if it has the right style elbow and the inlets on it, it will probaly work, see if the company can cross your # over. DUH I just look at the web site picture and that man. fits all later 153/181 engines with rochester carbs and mounting with 5 bolts

 

[trog100]

Re: Manifold Off...... argggggg

i would assume the 2.5 litre would equate with 153 cubic inches and 120 hp.... i think its the same manifold they sell for both capacity engines.. the port sizes differ on the head i think but they seem to be probably useing the same bigger port sized manifold for both 2.5 and 3.0 engines.. they probably use the same gasket as well..<br /><br />its probably the one u want but further checking is needed i recon..<br /><br />trog100

 

[Uncle Dave]

Re: Manifold Off...... argggggg

DD<br /><br />Make sure your carb will fit the repalcment mani.

 

[Darrendude]

Re: Manifold Off...... argggggg

My carb is a rochester but my manifold has 6 bolts holding it on to the head. These things are heavy so if I have to pay for shipping it will really add on costs. BTW I didnt break off a stud, it just came unscrewed from the block and they are short. The other 2 mangled studs came out easy aswell. I also found this number 4505212 on the end plate where the water goes in.<br /> After further inspection of the riser, I have decided to keep what I got. I steamed cleaned it out and wire wheeled everything on the outside and it will be fine for my application, no visable cracks and it didnt leak to start with.<br /><br />Thanks

 

[Uncle Dave]

Re: Manifold Off...... argggggg

DD<br /><br />Make sure your carb will fit the repalcment mani.

 

[Bt Doctur]

Re: Manifold Off...... argggggg

Darren, have one im getting rid of, good cond w/ riser (roound type)came off a 4 cyl. gm.<br />email "EJDSR251@aol"

 

[ziggy]

Re: Manifold Off...... argggggg

darren, cool that your broke bolts came out easy. broken bolt extraction can be a real drag. hope i get as lucky when i go to replaceing my manifold this spring. hope i get as lucky as you too and can reuse my old manifold. but i'm a pesimist and don't think i will get that lucky, time will tell. thanks for that web site. now i'm down to $363.50 for the manifold that fits my boat. cool.

 

[Darrendude]

Re: Manifold Off...... argggggg

Now that I have my old manifold off and I am waiting for the new one to come via ups, is there any benifit to maybe sanding and polishing the ports on the head?<br /><br />Thanks

 

[Reel Poor]

Re: Manifold Off...... argggggg

Not enough benefit here to risk getting some of material you removed into the engine. Porting heads is technical and time consuming. Theres no margin for errors. Any mistake could be costly either financially or in performance. This is not a job I would recomend without proper tools and experiance especially with the head still on the engine. The most power gain comes from porting the valve bowls below valve seats and not at the ports anyway.

 

[jimmythekid]

Re: Manifold Off...... argggggg

porting/polishing head passages is for engines that will run very high rpms. Say 5500 to 8500 rpms. Your engine probly cant handle rpms that high. Id say it would diminish rather than increase the net power from your engine. Especially if you have a stock exhaust, it wont't help. At all.

 

[Darrendude]

Re: Manifold Off...... argggggg

Thanks guys, it was just an idea. But I wont waste my time polishing ports.